
    #calculater{
        margin: auto;
        margin-top: 30px;
        border: solid 6px #000;
        border-spacing: 0px;
        border-radius: 10%;
    }
    #display{
        width: 100%;
        height: 50px;
        border-bottom: solid 4px #000;
         font-weight: bold;
         color: #193D83;
        font-family: 黑体;
        padding-left: 2px; 
        text-align: right;       
    }
    .numberkey{
        cursor: pointer;
        width: 60px;
        height: 45px;
        border: solid 1px #FFFFFF;
        background: #000;
        color: #ffffff;
        text-align: center;
        font-weight: bold;
        font-family: 黑体;
        border-radius: 30%;
    }
    #result{
       cursor: pointer;
       width: 40px; 
       height: 100%;
       background: #000;
        border: solid 1px #FFFFFF;
        color: #ffffff;
        text-align: center;
        font-weight: bold;
        font-family: 黑体; 
    }
    .numberkey:hover{
       background: #EA6F30; 
    }
    #result:hover{
       background: #EA6F30; 
    }